The principal aim of this project is to elucidate the molecular mechanism of active transport in bacterial organism. In the simple fermentative organism, Streptococcus faecalis it is known that cellular accumulation of K ion and certain amino acids is coupled to ATP hydrolysis by an ATPase associated with the plasma membrane. In order to understand the coupling mechanism we are attempting to characterize the protein subunits in the ATPase and in the membrane sector with which the enzyme is associated. More particularly we are trying to isolate the protein components that are part of the "proton-channel" envisaged by the chemiosmotic theory. We are also attempting to determine the role of non-exchangeable tightly bound nucleotide that is present in the isolated soluble form of the ATPase. Experiments are planned to show whether or not energization of the ATPase bound to a coupling membrane will alter nucleotide binding affinity as envisaged by the conformational coupling theory of energy transduction. We are also trying to characterize a small peptide segment in the ATPase molecule which is involved in the attachment of the enzyme to the plasma membrane.